1. Technical Field
The present disclosure relates to the field of sample rate synchronization. In particular, to a system and method for sample rate adaption.
2. Related Art
In a typical touch sensitive device able to render content on a LCD screen, the rendering frequency is locked to the occurrence of the vertical sync (“v-sync”), for example at 60 Hz.
When a user applies a continuous “swipe” across the touch-sensitive device, the finger position is sampled at a frequency that may differ from the v-sync frequency.
The touch panel frequency may vary slightly. Additionally, the “v-sync” signal and the “touch” signal may not be “phase-locked”, e.g. the phase delay between a “v-sync” sample and a “touch” sample may vary over time.
In a typical scenario, the touch input drives content to be rendered on the screen. A simple example would be a circle to be drawn to track the finger (touch) location.
Given the characteristics of the signals as explained above, a set of problems arise:    At a given render time, there might be more than one touch sample available, for example when the “touch” signal sampling frequency exceeds the “v-sync” signal frequency.    At a given render time, a given touch sample is stale by the phase difference between the time the rendering starts, and the time the touch sample is taken.    More importantly, the above-mentioned phase difference is not constant.
Perceptually, the lack of consistency in the phase difference results in “jitter” in the content rendered on the screen in response to, for example, a continuous finger “swipe”.